Fisher and Sterne had made their intentions clear by hitting opening birdies on the east course, before Sterne nudged ahead with consecutive birdies on the sixth and seventh.

Fisher wrested the lead with three consecutive birdies of his own, but consecutive bogeys on the 10th and 11th handed the initiative back to Sterne.

Fisher followed his two bogeys with two birdies before both players bogeyed the 15th. Their respective birdies on the final hole ensured they maintained their healthy advantage over the rest of the field.

Chase: Former Masters champion Charl Schwartzel is one of four players five shots behind the leaders

Chile's Felipe Aguilar and South African George Coetzee both hit rounds of 67 to join Van Zyl and Schwartzel in the tie for third.

David Drysdale and Tommy Fleetwood were the best-placed Britons in a five-way, 12-under tie for eighth, with Tom Lewis a further shot back.